1. Field of the Invention
The substitution of other types of vehicles for internal combustion engine driven vehicles is today recognized as being desirable for both energy conservation and environmental reasons. The development and use of noninternal combustion trackless-roadway vehicles with an on-board energy supply has been inhibited by the lack of high capacity, lightweight, compact energy sources. Electric vehicles using external energy lack the internal combustion vehicles' mobility, the ability to go anywhere. This invention describes means for using either an internal source of energy or an external underground source of electricity as circumstances warrant. More particularly, this invention describes means applicable to roadway vehicles for:
A. Automatically engaging and disengaging energy collecting contactors from underground power rails while the vehicle is in motion or is stationary. PA1 B. Maintaining contact with the power rails in spite of deviations in the path of the vehicle from the line of the power rails. PA1 C. Automatic switching between the internal and the external energy sources as required or desired. PA1 A. U.S. Pat. No. 3,547,237 describes a remotely controlled pickup for trackless electric vehicles operating from overhead power lines. The undesirable appearance and the safety problems inherent in overhead power lines are not presented by the underground power lines of the present invention. PA1 B. U.S. Pat. No. 3,637,956 describes a vehicle that operates from batteries or from power lines located on the surface of the road. The problems involved with power lines on the road surface relating to safety, vulnerability to weather conditions, and maintenance required are solved in the present invention by having the power lines underground. PA1 c. U.S. Pat. No. 3,914,562 and U.S. Pat. No. 4,007,817 describe a vehicle and roadway, respectively, embodying means for inductively coupling power to the vehicle from power lines beneath the roadway surface. The transmission of power from a one-turn primary by induction across an air gap (between the magnetic circuit of the vehicle and the magnetic circuit of the roadway) is inefficient due to low flux density and large leakage reactance. In the present invention the use of direct contact to the power rails results in low power loss in transfering power from the source to the vehicle.
2. Description of the Prior Art
Trackless-roadway electric vehicles capable of operating from batteries or from an external source disclosed in prior art include: